This post makes no sense whatsoever, for a whole lot of reasons.

1. If this were some covertly installed device, would it have a government attributable IP address?

2. If it were being used for surveillance, why would it be visible at all, instead of being on the other side of a passive optical tap?

3. If it’s really on the same broadcast domain as you, and on some other IP subnet, how can you talk to it?

4. You can configure a device on a network to use any IP address. Why do you think that means it belongs to the government?